<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id="app">
        <h2>{{getTime}}</h2>

        <div>{{getTime}}</div>
     </div>
 
     <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
     <script>
         let vm = new Vue({
             el : '#app',
             data :{},
             methods:{},
             computed : {
                getTime(){
                     let time = new Date();
                     console.log("time method");
                     return `${time.getFullYear()}-${time.getMonth()+1}-${time.getDate()}`;
                }
             }
         });
     </script> 
</body>
</html>